DTC Descriptors
DTC P0112: Intake Air Temperature (IAT) Sensor Circuit Low VoltageDTC P0113: Intake Air Temperature (IAT) Sensor Circuit High Voltage
Diagnostic Fault Information
Important: Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
Circuit | Short to Ground | High Resistance | Open | Short to Voltage | Signal Performance |
|---|---|---|---|---|---|
IAT Sensor Signal | P0112 | P0113 | P0113 | P0113 | -- |
Low Reference | -- | P0113 | P0113 | P0113 | -- |
Typical Scan Tool Data
Circuit | Normal Range | Short to Ground | Open | Short to Voltage |
|---|---|---|---|---|
IAT Sensor Signal | -39 to +120°C (-38 to +248°F) | 150°C (302°F) | -40°C (-40°F) | -40°C (-40°F) |
Low Reference | -- | -- | -40°C (-40°F) | -40°C (-40°F) |
Circuit/System Description
The intake air temperature (IAT) sensor is a variable resistor. The IAT sensor has a signal circuit and a low reference circuit. The IAT sensor measures the temperature of the air entering the engine. The control module supplies 5 volts to the IAT signal circuit, and a ground for the IAT low reference circuit. When the IAT sensor is cold, the sensor resistance is high. When the air temperature increases, the sensor resistance decreases. With high sensor resistance, the control module detects a high voltage on the IAT signal circuit. With lower sensor resistance, the control module detects a lower voltage on the IAT signal circuit.
Conditions for Running the DTC
P0112
| • | DTCs P0116, P0117, P0118, P0502 (if applicable), P0503 (if applicable), P0608, P0609 are not set. |
| • | The engine run time is more than 10 seconds. |
| • | The vehicle speed sensor (VSS) indicates that vehicle speed is more than 40 km/h (25 mph). |
| • | The engine coolant temperature (ECT) is less than 123°C (253°F). |
| • | This diagnostic runs continuously when the above conditions are met. |
P0113
| • | DTCs P0101, P0102, P0103, P0116, P0117, P0118, P0502 (if applicable), P0503 (if applicable), P0608, P0609 are not set. |
| • | The engine run time is more than 180 seconds. |
| • | The VSS indicates that vehicle speed is less than 24 km/h (15 mph). |
| • | The mass air flow (MAF) is less than 10 g/s. |
| • | The ECT is more than 60°C (140°F). |
Conditions for Setting the DTC
P0112
The control module detects that the IAT sensor parameter is more than 130°C (266°F) for more than 18 seconds.
P0113
The control module detects that the IAT sensor parameter is less than -36°C (-33°F) for more than 110 seconds.
Action Taken When the DTC Sets
DTC P0113 and P0113 are Type B DTCs
Conditions for Clearing the DTC
DTC P0113 and P0113 are Type B DTCs
Diagnostic Aids
When the vehicle is at ambient temperature, the IAT sensor and the ECT sensor should be relatively close to each other. Refer to Temperature Versus Resistance - Intake Air Temperature Sensor .
Reference Information
Schematic Reference
Connector End View Reference
Electrical Information Reference
DTC Type Reference
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the IAT sensor.
- Ignition OFF, test for less than 5 ohm of resistance between the low reference circuit terminal E and ground.
- Ignition ON, verify the scan tool IAT parameter is less than -36°C (-33°F).
- Install a 3A fused jumper wire between the signal circuit terminal D and the low reference circuit terminal E. Verify the scan tool IAT parameter is greater than 138°C (280°F).
- If all circuits test normal, test or replace the IAT sensor.
| ⇒ | If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the control module. |
| ⇒ | If greater than the specified range, test the signal circuit terminal D for a short to ground. If the circuit tests normal, replace the control module. |
| ⇒ | If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the control module. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
